Replaced non existing homepage route with admin dashboard route

Resources/views/Admin/Field/impersonating.html.twig

@@ -12,5 +12,5 @@ file that was distributed with this source code.
 {% extends 'SonataAdminBundle:CRUD:base_list_field.html.twig' %}
 
 {% block field %}
-    <a href="{{ url('homepage', {'_switch_user': object.username}) }}">{{ "switch_user"|trans({}, 'SonataUserBundle')}}</a>
-{% endblock %}
+    <a href="{{ url('sonata_admin_dashboard', {'_switch_user': object.username}) }}">{{ "switch_user"|trans({}, 'SonataUserBundle')}}</a>
+{% endblock %}